Ikoria: Lair of Behemoths

Archipelagore | Creature | Leviathan | Mutate {5}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Whenever this creature mutates, tap up to X target creatures, where X is the number of times this creature has mutated. Those creatures don't untap during their controller's next untap step. | Svetlin Velinov

Void Beckoner | Creature | Nightmare Horror | Deathtouch Cycling {2}{B} ({2}{B}, Discard this card: Draw a card.) When you cycle Void Beckoner, put a deathtouch counter on target creature you control. | Daarken

Yidaro, Wandering Monster | Legendary Creature | Dinosaur Turtle | Trample, haste Cycling {1}{R} When you cycle Yidaro, Wandering Monster, shuffle it into your library from your graveyard. If you've cycled a card named Yidaro, Wandering Monster four or more times this game, put it onto the battlefield from your graveyard instead. (Do this before you draw.) | Jesper Ejsing

Colossification | Enchantment | Aura | Enchant creature When Colossification enters the battlefield, tap enchanted creature. Enchanted creature gets +20/+20. | Johan Grenier

Greater Sandwurm | Creature | Wurm | Greater Sandwurm can't be blocked by creatures with power 2 or less. Cycling {2} ({2}, Discard this card: Draw a card.) | Grzegorz Rutkowski

Titanoth Rex | Creature | Dinosaur Beast | Trample Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.) When you cycle Titanoth Rex, put a trample counter on target creature you control. | Svetlin Velinov

Inspired Ultimatum | Sorcery | | Target player gains 5 life, Inspired Ultimatum deals 5 damage to any target, then you draw five cards. | Tyler Jacobson

Ruinous Ultimatum | Sorcery | | Destroy all nonland permanents your opponents control. | Chase Stone

Eerie Ultimatum | Sorcery | | Return any number of permanent cards with different names from your graveyard to the battlefield. | Jason A. Engle

Emergent Ultimatum | Sorcery | | Search your library for up to three monocolored cards with different names and exile them. An opponent chooses one of those cards. Shuffle that card into your library. You may cast the other cards without paying their mana costs. Exile Emergent Ultimatum. | Zack Stella

Genesis Ultimatum | Sorcery | | Look at the top five cards of your library. Put any number of permanent cards from among them onto the battlefield and the rest into your hand. Exile Genesis Ultimatum. | Jason Rainville